Measurement invariance in studies of social change in Ukrainian society

The article applies the method of multigroup confirmatory factor analysis (MGCFA) to test the hypothesis of measurement invariance of the integral index of social well-being (IISS-20) in the longitudinal (trend) study “Ukrainian Society: Monitoring Social Changes” in 1995-2010. Although this index, developed by Ye. Golovakha and N. Panina, has been crucial for studies of social change of Ukrainian society over the past 30 years, the measurement invariance of this theoretical construct has not been tested for any version of the instrument (IISS-44, IISS-20, IISS-13). The need for such a study stems from the transformations of society, when people may form different perceptions of their social well-being as well as the occurrence of significant changes in the population structure. If measurement invariance is not confirmed, then comparing the values of the indicator and its meaningful interpretation are problematic. Since the quality of the basic model of the shortened version of the index IISS-20 did not allow to proceed with a test of measurement invariance for this particular adaptation of the instrument during the chosen period, it was modified by removing components that had caused multicollinearity. For the resulting optimized model we confirmed the configural, metric and scalar measurement invariance of social well-being for the period that comprises four waves (1995, 2000, 2005, 2010) of the survey by the Institute of Sociology of the NAS of Ukraine. Thus, the result of our analysis with the technical modification of the IISS-20 questionnaire is in line with evolution of the instrument. It proves the possibility of both valid comparisons in terms of the structure of the latent variable and the comparability of the means of the integral index of social well-being between different groups and research waves over time. The article, therefore, demonstrates the explanatory power of this important sociological tool for monitoring Ukrainian society and research of social change.